DVD movies are encrypted using "CSS (Content Scrambling System)", which is intended to prevent DVD movies from being digitally copied. In 1999, a 16-year-old genius invented a method of decrypting the CSS, called DeCSS. Oddly enough, DeCSS is illegal, but DVD ripper utilities are not !!! This is because DeCSS actually finds the 409 encryption keys, while the rippers just decrypt the files without generating the keys . . . go figger !!
There are really only two DVD rippers worth using - DVD Decryptor (free) and Smart Ripper. Both will make a perfect copy of your DVD folder and file structure onto your hard drive, and will also remove the encryption.
I use DVD Decryptor. It has 3 modes, File, IFO, and MDS. Once you use DVD Encryptor to rip the DVD to your hard drive, you can then use a program such as DVD2ONE to burn the file to a DVD. Although DVD2ONE will work with files that are preprocessed (ifo mode), it is strongly recommended to use file mode.
ISO mode makes one huge ISO file. You can use a Daemon to mount the ISO as a drive and play the DVD on your PC – Daemon Tool 3.29 works perfectly for that. Daemon's "trick your PC" into thinking that a file or folder is an actual drive. However, there is no reason to use ISO mode, since file mode will work with standard PC DVD players such as Power DVD and do not require a daemon.
Why Rip ??
It seems silly to rip a DVD. Why not just play the DVD directly? The reason, is for those who wish to either examine and learn about the DVD format and file structure, or for those who wish to copy a DVD the hard way. That would be to rip the DVD, and then burn the resulting data to a DVD. Of course, you can make that intermediate step transparent by purchasing a DVD copy utility such as DVDxCOPY. It can rip, burn, and delete the DVD files from your hard drive all in one process
The Story of DeCSS
Computer software to decrypt CSS was released to the Internet in October 1999, although other "ripping" methods were available before that. The difference between circumventing CSS encryption with DeCSS and intercepting decrypted, decompressed video with a DVD ripper is that DeCSS can be considered illegal under the DMCA and the WIPO treaties. The DeCSS information can be used to "guess" at master keys, such that a standard PC can generate the entire list of 409 keys, rendering the key secrecy process useless.
The supporters of DeCSS point out that it was only developed to allow DVD movies to be played on the Linux operating system, which had been excluded from CSS licensing because of its open-source nature. This is specifically allowed by DMCA and WIPO laws. However, the DeCSS.exe program posted on the Internet is a Windows application that decrypts movie files. The lack of differentiation between the DeCSS process in Linux and the DeCSS.exe Windows application is hurting the cause of DeCSS backers, since DeCSS.exe can be used in the process of copying and illegally distributing movies from DVD. See OpenDVD.org and Tom Vogt's DeCSS central for more information on DeCSS.
Shortly after the appearance of DeCSS, the DVD CCA filed a lawsuit and requested a temporary injunction in an attempt to prevent Web sites from posting (or even linking to!) DeCSS information. The request was denied by a California court on December 29, 1999. On January 14, 2000, the seven top U.S. movie studios (Disney, MGM, Paramount, Sony [Columbia/TriStar], Time Warner, Twentieth Century Fox, and Universal), backed by the MPAA, filed lawsuits in Connecticut and New York in a further attempt to stop the distribution of DeCSS on Web sites in those states. On January 21, the judge for the New York suit granted a preliminary injunction, and on January 24, the judge for the CCA suit in California reversed his earlier decision and likewise granted a preliminary injunction. In both cases, the judges ruled that the injunction applied only to sites with DeCSS information, not to linking sites. The CCA suit is based on misappropriation of trade secrets (somewhat shaky ground), while the MPAA suits are based on copyright circumvention. On January 24, 16-year old Jon Johansen, the Norwegian programmer who first distributed DeCSS, was questioned by local police who raided his house and confiscated his computer equipment and cell phone. Johansen says the actual cracking work was done by two anonymous programmers, one German and one Dutch, who call themselves Masters of Reverse Engineering (MoRE).
This all seems to be a losing battle, since the DeCSS source code is available on a T-shirt !!!